Freight car classification yards



Oct. 27, 1964 J. G. KARLET ETAL 3,154,023

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THEIR. ATFDBJVE'I zfi bx Oct. 27, 1964 Filed Dec. 12, 1957 United States Patent ()fi a 3,154,923 Patented -Oct. 27, l 964 3,154,023 FREIGHT CAR CLASSIFICATION YARDS Joseph G. Karlet, Roanoke, Va, and Albert S. Tabor, Portsmouth, Ohio, assignors to Westinghouse Air Brake Company, Wilmerding, ?a., a corporation of Pennsylvania Filed Dec. 12, 1957, Ser. No. 702,416 Claims. (Cl. 104-26) This invention relates to the classification of freight cars, and particularly to an improved classification yard therefor.

In the handling of freight carried by railway cars, it is necessary to provide locations at which the cars in a train may be regrounded to form other trains consigned to difierent destinations. It is the current practice for this purpose to provide classification yards in which a plurality of storage tracks, each of which may be up to 6000 feet in length, are laid out in a ladder formation diverging from a common hump track, each storage track being approached from the hump over a route including a plurality of switches. In such a yard, each classification in which incoming cars may be placed is defined by one or more such storage tracks. Since the storage tracks are parallel, in order to build up a train from cars so classified, it is necessary for a yard engine, usually working from the opposite end of the yard from the hump end, to enter each individual track, pick up a cut of cars, reverse its motion, move out of the first track and then onto a second track to pick up a second cut of cars. This cycle continues until the train is built up. Such operation may require a considerable length of time.

It is an object of our invention to provide a classification yard in which trains can be made up with a single reverse and forward movement of a locomotive, and in which freight cars may be classified in a desired train order as they are humped. In conventional yards, the parallel arrangement of storage tracks makes it necessary to acquire large tracts of land adjacent the main right-ofway, which is always expensive, and in many cases is impractical due to the topography of the adjacent terrain. It is a further object of our invention to provide a classification yard which does not require extensive land adjacent the right-of-way.

Various systems have been devised for automatically controlling the speeds of cuts of cars being classified in conventional yards to prevent stalling or unduly forceful coupling. For this purpose, conventional yards are usually provided with car retarders located along each route from the hump to the storage tracks. For economic reasons, it is usual to place the last retarder in each route at a point common to six or even eight storage tracks. Cuts leaving the last retarder in a yard so arranged may travel from 300 to up to 6000 feet, depending on the fullness of the storage tracks, before reaching their assigned storage track designations. Obviously, toproperly control the terminal or coupling velocity of cuts under these conditions requires complex, sensitive and accurate apparatus. It is a further object of our invention to reduce the requirements on such control apparatus, or even to eliminate it entirely, by providing an improved classification yard in which each cut will have a minimum distance to roll from the last speed control location to the point of coupling.

It is a more particular object of our invention to provide, in a classification yard of the class described, .a

plurality of storage tracks each approached from a common running track over a route including a plurality of speed control devices, in which the free-rolling distance beyond each control device is reduced to a minimum.

It is a further object of our invention to provide a classification yard in which many of the switches required to define the classification routes can be operated by relatively inexpensive spring mechanisms, rather than by power or manual operation as is currently required in ladder type yards of the kind referred to above.

It is a further object of our invention to provide improved car speed control devices for classification yards.

Other objects and further advantages of our invention will be apparent to those skilled in the art as the description proceeds.

In practicing our invention, we provide a single running track having a suitable car accelerating device, such as a hump, located at its entrance end, and having a master retarder following the hump. A pair of tracks are located parallel to the main running track and on either side thereof. Each of these tracks is approached from the main running track over a plurality of crossovers, the stretches of tracks between crossovers thus formed comprising pocket tracks which are employed for the classification of cars. The running track and its associated pocket tracks which are thus provided may be used to make up two parallel trains of cars classified according to a predetermined order, or, depending on the length of the pocket tracks, may be employed to form any seriesparallel array of sets of cars classified in a predetermined order. If so desired, a plurality of groups of such train classification areas may be provided in a ladder formation, to provide for the make-up of any desired number of trains.

In accordance with one specific embodiment of our invention, we provide a pair of classification tracks approached over crossovers from a centrally disposed running track to form a plurality of pocket tracks, the facing point end of each crossover being provided with a power operated switch, and the trailing end of each crossover being provided with a spring switch.

In accordance with another particular embodiment of our invention, in conjunction with a classification yard having pocket trunks approached over crossovers from a main running track in the manner described above, we provide car speed control devices in advance of each crossover to control the speed of the cars approaching the crossovers to values sufiicient to either couple on the adjacent pocket tracks, or to move to the next car speed control device, as determined by the route of the cars.

In carrying out the last-mentioned embodiment of our invention, we may employ a car speed control device comprising an impeller of a first kind in which dogs adapted to engage the rear axle of a moving car are disposed on a continuous belt, means being provided for controlling the movement of the belt to position one of the dogs behind the rear axle of each cut as it occupies a track section associated with the accelerator. Alternatively, We may employ a second form of impeller in which a belt having a continuous tread adapted to engage the side frames of the trucks of freight cars is controlled to move at a fixed desired speed and is brought into engagement with the trucks of cars occupying a track section associated with the impeller by means controlled by the occupancy of the track section. Further,

3 as will appear as the description proceeds, we may employ other known types of car speed control devices, and we may even, in accordance with another embodiment of our invention, employ conventional car retarders to control the speed of cars moving through the yard in accordance with our invention.

We shall first describe various embodiments of our invention in detail, and shall then point out the novel features thereof in claims.

In describing our invention, and the various illustrated embodiments thereof, we shall employ similar reference characters to designate similar elements in each of the several views. Further, in order to simplify the drawings, we shall employ conventional symbols comprising the characters B and N to designate the positive and negative terminals, respectively, of a conventional source of DC. voltage which is used to operate certain components of the apparatus associated with our invention, this power supply not being otherwise shown, since such devices are Well known in the art.

In the drawings, FIGS. 1a and 1b, when placed sideby-side, comprise a schematic diagram of a classification yard in accordance with one embodiment of our invention.

FIGURE 2 is a schematic diagram of a classification yard in accordance with a second embodiment of our invention.

FIGURE 3 is a partial elevational view of the classification yard of FIG. 2, showing typical relative grades.

FIGURE 4 is a schematic diagram of a car speed control device which may be employed in a yard of the type shown in FIG. 1.

FIGURE 5 is a schematic view, partly in section, of a second form of a car speed control device which may be employed in a classification yard of the type shown in FIG. 1.

Referring now to FIGS. 1a and 1b, we have shown a classification yard in which a main running track 1 is approached over a suitable car accelerating device, here shown as a hump having an apex indicated by a dotted line. A pair of tracks 2 and 3 are disposed parallel to track 1 as shown.

Each of tracks 2 and 3 is divided into a series of classification pocket tracks by a series of crossovers, each comprising a first switch located on track 1 and a second switch located on the storage tracks, except that the first such crossover for each of the storage tracks does not require a swich on the storage lead. These switches are shown schematically, since they may be of well known conventional construction. The symbols employed are also conventional, switch 1W, for example, being shown as a power operated switch, and switch 5W being shown as a spring switch. The power operated switches may be controlled in any conventional manner, by suitable automatic switching means, or by an operator, in a tower located in the yard, manipulating control levers electrically connected to the switch machines in a manner known per se. The spring switches are normally aligned for spring-opposed movement into the storage tracks from the main track and for unopposed movement over the switches in either direction on the storage tracks, as schematically indicated.

In particular, track 2 is divided into a plurality of pocket tracks 1ST, 3ST, 5ST and 7ST, although more or less pocket tracks could obviously be provided within the scope of our invention if so desired. Pocket track 1ST is approached from track 1 over power operated switch 1W in its reverse position. Storage track 3ST is approached from track 1 over a power operated switch 4W in its reverse position on track 1 and a spring switch 5W on track 2. Similarly, pocket track 5ST is approached from track 1 over a power operated switch SW and a spring switch 9W, and pocket track 7ST is approached irom track 1 over a power operated switch 12W and a spring switch 14W. As shown, pocket track section 7ST is connected back to track 1 over a power operated switch 16W in its reverse position, although this last storage track could be connected to any other output track it so desired.

In the same way as described for track 2, track 3 is divided into a plurality of pocket storage track sections 2ST, 4ST, 6ST and 851 by crossovers comprising power operated switches 3W, 6W, W and 13W and spring switches 7W, 1 1W and 15W. As shown, the last pocket track section SST on track 3 may be returned to track I over a power operated switch 17W in its reverse position if so desired.

Each of pocket tracks lST-dST may be relatively short compared to conventional ladder type storage tracks, in view of our improved classification method, as will appear. For example, in practice these pocket tracks may be approximately 650 feet in length. While only eight pocket tracks are shown, any desired number may be employed, and in a typical practical installation, ten pocket tracks would be provided on each side of classification track ll.

As schematically indicated, each of pocket tracks is provided with a skate 13 located adjacent the exit end of the pocket track to prevent cars from rolling out of the pocket track sections until it is desired to make up a train. If desired, these skates could be replaced by simple retarders or other car stopping devices without eparting from our invention.

As illustrated in FIG. 1a auxiliary tracks, such as the repair track approached from track 1 over switches 1W and 2W in their reverse positions, may be provided for repair or hold purposes if so desired.

As is known, it is necessary to provide speed control for cars rolling from a hump or other accelerating device into classification tracks in order to prevent damage to lading due to cars coupling with preceding cars at high speeds, as well as to avoid loss of time due to cars stalling before reaching their destinations. For this purpose, in accordance with the embodiment of our invention shown in FIGS. la and 1b, we first provide a master retarder 4 following the hump. Master retarder 4 may be of conventional design and construction, and may be controlled in any suitable conventional manner to reduce the leaving speed of cuts emerging from the retarder to values which will permit the cuts to reach an impeller 5 located in advance of switch 1W. For example, United States Letters Patent No. 2,331,125, granted October 5, 1943 to J. W. Logan, Jr., for Railway Braking Apparatus, shows retarder control means suitable for use with our invention.

Impeller 5, which may be of one of the types shown in more detail in FIGS. 4 and 5, to be described, or may be of any known conventional construction, is adjusted to provide a fixed leaving speed for each cut. For example, this impeller may be set to control the speed of cars to five miles per hour. For the purpose of controlling the operation of this impeller, an impeller control 6 is provided, which may be of one of the forms which will be described in more detail in connection with FIGS. 4 and 5.

The track layout in accordance with this embodiment of our invention is so graded that a cut of cars leaving impeller 5 at five miles per hour will be able to roll into contact with skates 13 on pocket track 1ST or 2ST with either switch 1W or switch 3W, respectively, in its reverse position, or will reach impeller 7 if these switches are in their normal positions. Normally, a substantially uniform grade of between 0% and 0.2%, which will be non-accelerating for most cars, may be employed.

Impellers 7, 9 and 11 may be identical with impeller 5. As shown, an impeller control 8 is associated with impeller 7 in the same manner as previously described for impeller 5. Similarly, an impeller control 10 is associated with impeller 9, and an impeller control 12 is associated with impeller control 11. Each of these impellers is adjusted to bring the speed of cars moving thereover to a fixed desired speed, such as five mile per hour, which will permit the cars to reach either the skate on one of the adjacent pocket tracks, or the next impeller, depending on the selected destination for the car.

In some practical applications of our invention, it may be desirable to dispense with the first impeller 5. In such a case, master retarder 4 would be set to provide a leaving speed which would permit each cut to reach the next impeller, here shown as impeller 7.

In order to illustrate the operation of the embodiment of our invention shown in FIGS. 1a and 1b, it will be assumed that it is desired to classify an incoming train of randomly arranged cars into two trains consigned to different final destinations, each train having three different intermediate destinations where it is desired to cut out one or more cars in the train.

As cars on the incoming train arrive at the hump, cuts are uncoupled and pushed over the hump, each cut consisting of a number of coupled cars having a common destination. Let it be assumed that the first cut is consigned to the third destination for a first train and that the second cut is consigned to the first destination for the first train. As the first cut is pushed over the hump, switches 1W, 3W, 4W and 6W may be left in, or set to, their normal positions, and switch 8W will be set to its reverse position. The remaining switches in the yard may be left in their existing positions. As the first cut traverses master retarder 4, it will be brought to a fixed leaving speed; for example, four miles per hour, in a conventional manner by any suitable operation of the master retarder known per se. As the cut traverses impeller 5, it will be accelerated to a leaving speed such as five miles per hour, which will enable it to reach impeller 7.

When the first cut has cleared switch 1W, this switch may be set to its reverse position. The second cut may now roll down from the hump, occupy the master retarder and be accelerated by the impeller 5. While the first cut is traversing switches 3W, 4W and 6W in their normal positions, the second cut may enter pocket track section 1ST, and there either couple with preceding cars or engage skate 13, after whichit will come to a stop.

When the first cut reaches switch 8W, which has been set to its reverse position as previously described, it will proceed over spring switch 9W into pocket track section 5ST and then into engagement with s ate 13. With spring switch 9W positioned as shown, the wheels of the first cut will move the points of the switch against the force of the spring in a conventional manner to enable the cut to enter pocket track 5ST. Thereafter, moves may be made over track 2 in either direction over switch 9W without spring resistance.

When the second cut has cleared switch 1W, this switch may be repositioned for a following cut. Assuming that this next cut is consigned to the second destination for a second train, it will be routed over switches 1W, SW and 4W in their normal positions and switch 6W in its reverse position to occupy pocket track section 4ST. Classification in the manner just described will be continued until all of the incoming cars are stored in either track 2 or track 3 in cuts arranged in the inverse order in which the destinations of the cuts will be reached, thus eliminating the need for extensive switching maneuvers as each cut reaches its destination.

With each of the outbound trains arranged in order on tracks 2 and 3 in the manner described, a first train may be made up by manually or automatically removing the skates 13, or disabling such other car stopping devices as might be provided in their place, and backing a locomotive from track 1 over switch 16W in its reverse position until the locomotive couples with the first cut of cars in pocket track section 7ST. This move will be continued, with the cars of the train now moving in the facing point direction over spring switches 14W, 9W and 6 SW, until the entire train is coupled together. The locomotive can now move ahead and proceed directly out onto track 1 without further loss of time. A second loco-' motive can now back into track 3 over switch 17W in its reverse position and make up the second train by a sim ple reverse and forward motion.

Referring now to FIG. 2, a second embodiment of our' invention is shown in which retarders are employed throughout the yard for speed control.

In accordance with this embodiment of our invention, main track 1 has the apex of a hump, or any other suitable accelerating device, located at its entrance end as before, and a master retarder 4 is provided following the apex of the hump for preliminary speed control. To il lustrate the flexibility of layout possible with our invention, a first power operated switch 35W is shown following the master retarder 1, which, when set to its reverse position, routes cars leaving the master retarder to a second'main running track 21. Switches 36W and 37W, in their reverse positions, may be used to route cars running over switch 35W in its normal position to classificationtrack 2 or 3, respectively. As in the preceding embodiment of our invention, tracks 2 and 3 are divided into a plurality of pocket tracks such as 1ST, 3ST and 2ST, 4ST, respectively, by a plurality of crossovers comprising power operated switches 36W, 37W, 21W, 23W, 26W and 28W located on track 1 and spring switches 24W, 25W, 39W and 31W located on storage tracks 2 and 3 as shown. Storage tracks 20 and 22, adjacent track 21, may be divided into pocket tracks in the same manner, to form an additional storage area, and in-the same way, other storage areas could be formed. However, since the details of such additional storage areas would merely repeat the showing of the area associated with track 1, they have notbeen shown.

Each of pocket tracks lSTthrough 4ST is provided with a suitable car stopping device, such as skate 13, as shown. Further, in accordance with this embodiment of our invention, the end ofeach pocket track is provided with a safety spur 32 approached from the-pocket track over a power operated switch which is normally set to connect the pocket track to the safety spur. In particular, pocket track 1ST is connected to its associated safety spur 32 over switch 20W in its normal position, and switches 22W, 27W and 29W are similarly arranged in pocket tracks 2ST, 3ST and 4ST, respectively.

A car retarder is located in advance of each set of pocket tracks. For example, carretarder 4 serves as the retarder in advance of pocket tracks 1ST and 2ST, car retarder 33 is located in advance of pocket tracks 3ST and 4ST, and car retarder 34 is located in advance of the nextfollowing pair of pocket tracks, not shown.

Car retarders 4, 33 and 34, and other car retarders which may be provided, may be controlled in any conventional manner well known in the art to reduce the speed of cars passing therethrough to values selected in accordance with the weight or rolling characteristicsof the car or in accordance with other desired characteristics. Since suitable control .systems for such retarders are known per se, and their details do not form a part of our invention, they are not shown. However, Patent ,No. 2,331,125, for example, referred to above, shows a retarder control which might be used for this purpose if so desired. The leaving speed from the retarders is selected such that each car will retain suflicient momentum to reach the skate in either of the next adjacent pocket tracks. This will be better understood by reference to FIG. 3, in which the relative grades of the tracks in a yard in accordance with this embodiment of our invention are schematically illustrated.

Referring now to FIG. 3, the grades of typical tracks in a yard in accordance with FIG. 2 are shown with respect to a dottedline representing 0% grade. In order to illustrate the principles involved, the grades of the various tracks have been greatly exaggerated. Further, in order to avoid complicating the drawing, only the portion of the yard including tracks 1 and 2 and a part of pocket track 2ST has been shown, the remainder of the yard being similarly arranged. As shown, the grade of track 1 rises to a maximum value to the apex of the hump and then begins a substantially uniform descent on an accelerating grade which is continued to the end of the track. The grade of pocket track 1ST is upward from switch 35W to end switch 20W. Safety spur 32 for pocket track 1ST is located on a rapidly increasing grade to safely and positively stop cars entering thereon. Switch 20W is connected to switch 24W over a stretch of track of descending grade, and switch 21W is connected to switch 24W over a stretch of track of increasing grade which continues into pocket track 3ST. In a similar manner, pocket track 3ST extends to a safety spur 32, having a rapidly increasing grade, over switch 27W in its normal position, and extends over a descending grade to switch 30W with switch 27W in its reverse position. Switch 30W is approached from switch 26W over a stretch of track of increasing grade.

In operation, it will be apparent from the above description that a car leaving any of the retarders and routed to one of the next adjacent pocket tracks will be decelerated to a speed lower than its retarder leaving speed, whereas a car routed to the next retarder will arrive there at an increased speed to provide a margin for further control. The operation of a yard in accordance with this embodiment of our invention to classify cars into a desired train order is otherwise the same as that described above in connection with the embodiment of FIGS. 1a and 1b Referring now to FIG. 4, an improved car impeller suitable for use in the classification yard of FIG. 1 is shown. Impeller 5 is shown associated with track sections IT and 2T, which may be formed in track 1 adjacent the first impeller location in FIG. 1, between retarder 4 and switch 1W, by insulated joints in a conventional manner. These track sections are provided with conventional track circuits, not shown, to control track relays 1TR and 2TR. As is conventional, relays 1TR and ZTR will be energized when their associated track circuits are unoccupied, and deenergized when their associated track circuits are occupied. While the reference characters employed associate the impeller of FIG. 4 with impeller 5 in FIG. 1, it will be apparent to those skilled in the art that the apparatus shown is also suitable for use in the other impeller locations of FIG. 1, the required track sections being formed between adjacent switch locations on track 1.

As shown in FIG. 4, impeller 5 comprises a continuous belt 35, of any conventional construction, which is adapted to pass around rollers 83 and 84, which are, in practice, mounted between the rails of track section 2T, in suitably supported journals. A pair of dogs 36 and 37 having ends 36a and 37a, respectively, formed to engage the rear axle A of a car C when either of the dogs is in the position shown in dotted lines, are mounted on belt 35 in any conventional manner, as by bolts or rivets.

To facilitate the illustration of our invention, the length of car C relative to track sections IT and 2T has been greatly exaggerated. In practice, the lengths of these sections would be so selected that they could not be spanned by a car.

Track relays 1TR and ZTR, as previously described, are connected to their respective track sections IT and 2T in conventional track circuits, not shown, such that relay 1TR closes its associated front contact a when track section 1T is unoccupied and opens front contact a when track section IT is occupied, and such that track relay ZTR closes its associated back contact a when track section 2T is occupied and opens this contact when the associated track section is unoccupied.

Impeller control 8, as shown in FIG. 4, comprises a conventional DC. motor 43 and an associated control circuit which will now be described. Motor 43 has a first energizing circuit which extends from terminal B of the battery over front contact a of track relay 1TR, back contact a of track relay ZTR, and through the winding of the motor to terminal N of the battery. Motor 43 has a second energizing circuit extending from terminal B of the battery over wiper 39 and contactor 33, to be described, and through the winding of the motor to terminal N of the battery. Motor 43 has a third control circuit which extends from terminal B of the battery over wiper 41 and contactor 40, to be described, and through the winding of the motor 43 to terminal N of the battery. When any of the energizing circuits for motor 43, just described, are closed, motor 43 will rotate at a fixed speed which may be selected in accordance with the desired impeller leaving speed.

Wipers 39 and 41 are driven from schematically indicated shaft 45 of motor 43 through a conventional reduction gear 42. Shaft 45 directly drives roller 84, and consequently belt 35, in the direction shown by the arrows. Reduction gear 42 is so selected that a 360 rotation of wipers 33 and 41 corresponds to a 360 movement of belt 35; that is, a movement suflicient to bring dog 36 around roller 84 and back to its original position.

Wipers 39 and 41 are initially positioned, as shown, out of contact with their associated contactors 38 and 40. As shown, contactors 38 and 40 occupy somewhat less than 180 degrees of the rotation of the wipers.

In the operation of the embodiment shown in FIG. 4, let it first be assumed that both track sections 1T and 2T are unoccupied and that track relays 1TR and ZTR are both energized. Accordingly, the first traced energizing circuit for motor 43 will be interrupted at back contact a of track relay ZTR. The second and third energizing circuits for motor 43 will also be interrupted, wipers 39 and 41 being in the positions shown and out of contact with their associated contactors 38 and 40. Motor 43 and belt 35 will accordingly remain stationary.

Next, let it be assumed that car C moves into section 1T, causing track relay 1TR to be released, and then moves into section 2T. When the car enters track section 21, track relay ZTR will become released, closing its back contact a. However, the first energizing circuit for motor 43 will be interrupted at this time at front contact a of track relay 1TR, and motor 43 will therefore remain deenergized.

When the car vacates track section 1T, track relay 1TR will become energized and will close its front contact a. The first traced energizing circuit for motor 43 will now be completed over front contact a of track relay 1TR and back contact a of relay ZTR, and motor 43 will begin to turn belt 35 in the direction shown by the arrows. When dog 36 is approximately in the position shown by the dotted lines, it will engage the rear axle A of car C and the car will then be impelled along the track and accelerated to the speed of belt 25. To this end, car retarder 4 in FIG. 1 must be set to bring the speed of car C below the speed of the impeller so that the car will not run away from the impeller.

As motor 43 begins to rotate, wiper 39 will come in contact with contactor 38 and will close the second energizing circuit for motor 43.

As car C leaves track section 2T, track relay ZTR will be picked up and will interrupt the first traced energizing circuit for motor 43 at its back contact 0. However, motor 43 will still be energized over wiper 39 and contactor 38 until dog 36 has been brought approximately into the position of dog 37 on roller 84 and dog 37 is brought to the initial position of dog 35. The motor will stop with wiper 39 just past the end of contactor 38 and wiper 41 just ahead of the beginning of contactor 4t).

Next, let it be assumed that a second cut enters track section ET, and then enters track section 2T and vacates track section IT as previously described. Track relay ITR will now be energized and track relay .2TR will be released, completing the first energizing circuit for motor 43. Motor 43 will begin to rotate, driving belt 35 until dog 37 engages the rear axle of the second car. As motor 43 begins to move, wiper 41 will engage contactor 40and will complete the third energizing circuit for motor 43.

When the second car vacates track section 2T, track relay ZTR will be energized and will interrupt the first energizing circuit for motor 43 as previously described. However, motor 43 will still be energized over its third energizing circuit, and will continue to rotate until wiper 41 clears contactor 40, at which time dogs 36 and37 will be restored to their initial positions. All of the apparatus will then be in the initial condition shown in the drawings.

Referring now to FIG. 5, we have shown a secondform of impeller which is adapted to be employed in a yard of the type shown in FIG. 1, and which results in a saving of equipment. In particular, track section IT in FIG. 4 and its associated track circuit and track relay may be omitted when the impeller of FIG. is employed.

As shown in FIG. 5, the impeller of this embodiment is adapted to be employed with a single insulated track section, which may correspond to track section 2T in FIG. 4. Track section 2T is electrically defined by insulated joints idas schematically indicated, and is provided with a track circuit for controlling track relay ZTR in a conventional manner as schematically indicated.

In this embodiment of our invention, cars are accelerated by force applied to the side frames of their trucks. A typical car is provided at each end with a truck, each truck having at either side a pair of wheels 55, journals 54, and a side frame 53. It has been found that side frames of freight cars are generally uniform in height above the track, and that the bottoms of these side frames are available for engagement by impelling apparatus located on either side of track sectionZT.

As shown in FIG. 5, a continuous belt 52 is adapted to engage side frames 53 of cars passing thereover, and is mounted about a drive pulley 51 and a movable clutch pulley 5'0. Pulley 51 may be journaled in fixed supports 58 as schematically indicated. In practice, one such'belt and pulley arrangement would be located on each side of the track at each impeller location.

Belt 52 may comprise a conventional endless chain 56 having rubber drive blocks 57 mounted thereon in any conventional manner, as indicated.

Pulley 59 is ournaled to one end of a movable support arm 59, which is pivotally mounted at the other end to a fixed support 69 as shown. In the position shown in the drawings, belt 52 would be slackened sufiiciently that it would not be driven by pulley 51. However, with force applied to arm 59 tending to move it in a counterclockwise direction about support so, belt 52 would be tightened and then would be driven in the direction shown by the arrows when pulley 51 is rotated in the direction of the arrow shown thereon. Pulley 5t) and its associated control means thus comprise a clutch for controlling the movement of belt 52.

In order to provide for adjustable movement of arm 1% and its associated pulley 54 we provide a cylinder 61 having a piston 62 slidably mounted therein and connected to a rod 63 which is adapted to slide in a suitable hole 6- in arm 59. A spring 65 is confined between a coiiar 66, which is secured to rod 63, and a collar 86, secured to arm 5%, as shown.

Cylinder at is pivotally mounted to a suitable fixed support 67. A suitable flexible conduit, as indicated at 63, is provided to connect cylinder 61 to a control valve 69.

Control valve 69 maybe ,of. anyconventional construction, but is here shown as-comprising a casing 70.having opposing chambers 71 and 72 separated by a chamber 73 to which conduit 68 isconnected. Located in chamber 71 is a valve member 74 having a stem .75 ,which extends upwardly through an opening in the .wall of chamber 72. Disposed above stem 75 is a centrally apertured valve member 76. A spring 77 is confined between the:upper part of valve member .76 and the wallof chamber 72 to force valve element 76 into sealing engagement with the lower walls of chamber .72 as shown. -Chamber 72 is connected to a suitable source of fiuidpressure,not;sho,wn, and chamber 71 is connectedto atmosphereor any other desired fluid return through a suitable aperture asshown.

A suitable valve magnet VM is connectedto stem 75 of valve element 74. When energized, valve magnet VM raises valve element 74 into sealing engagement withthe upper walls of chamber 71, carrying valve element -76 out of engagement with thelower walls of chamber 72 and connecting the fluid pressure sourceto conduit68. Valve magnet VM has an obvious energizing circuit which extends from terminal B of the battery over back contact a of track relay 2TR and through .the winding-of the magnet to terminal N of the battery.

A motor 80 has a driveshaft, schematically indicated at 81, connected to rotate pulley 51. As indicated, motor 80 has supplyleads connectedto terminals B and N of the'battery for continuous operation, although suitable power control switches could obviously be provided to at times interrupt the operation of motor 80 if so desired.

As indicated inFIG. 5, suitable support rollers illustratively indicated at 82 may be located along the upper span of belt 52 if so desired.

In operation, .with track section 2T unoccupied pulley 51 will be driven by motor 80. .With arm 59 andpulley 50 in the position shown, belt 52 will be slack and will not turn.

When a car occupies track section 2T and causestrack relay 2TR to be released, valve magnet VM will be energized overits previously traced circuit. Valve 69 will now respond to connect thefluid pressure source'to conduit .68 and piston 62 will be forced upwardly in cylinder 61 so that rod 63 will compress spring-65 and move arm 59 sufiiciently to tighten-pulley 50.

Belt 52 will now be driven in the direction of the arrows, engagingthe side frames .ofthe trucks of cars moving thereover. Eachbelt isset to move at a-speed of, say, five miles per hour. Accordingly, cars moving at greater speed will-be retarded by the belt, and cars moving at lower speeds willbe accelerated, sot-hat all cars will leave at the predetermined-speed set by the motor. The use of impellers of the type shown in --FIG. 5 in a system of the-kind shown. in FIG. 1 will therefore permit a less precise control to be used at the master retarder, since cars may approach the impellers at either lower or higher speeds than the impellers are set to produce.

When track section 2T is vacated, tnack relay 2TR will be energized, and valve magnet VM will be released, allowing spring 77 to restore valve elements 74 and 76 to the positions shown in the-drawing. Cylinder 61 will thereby be vented to atmosphere through conduit 68 and chambers 73 and, and the-apparatus will be restored to its initial condition.

While we have described various-embodiments of our invention in detail, it will-be apparent .to those skilled in the art that many changes and modifications in the detailed embodiments may be made without departing from the scope of our invention. Accordingly, we do not wish to be limited by the details shown, but only-by the scope of the following claims.

Having thus described our invention, what we cliam is:

1. The method of classifying a plurality of cars being assembled.,into a train for departure from a railroad yard, comprising, moving the cars to be classified along a single running track, switching said cars into selected sections of a second track in accordance with the predetermined destination of each car, the resulting group of cars in each section of said second track having the same destination along the route to be traveled by the train, and assembling the groups of cars in said second track into a complete train ready for departure by a single 1Zeverse movement of said cars along said second trac 2. The method of classifying a received train of cars in a railroad yard for further dispatch, comprising, moving preselected cuts of cars from said train along a single running track, switching said cuts into selected sections of at least one other track paralleling said running track in accordance with predetermined destinations of said cuts, all cuts of cars switched into a particular section having the same destination, and assembling the cars in a single parallel track into a train ready for departure by a single coupling movement along that parallel track to couple all the blocks of cars into a complete train.

3. The method of classifying a plurality of cars being assembled into a train for departure from a railroad yard, comprising, moving the cars to be classified along a single running track, switching said cars over a plurality of crossovers into selected sections of a second track in accordance with the established destination of each car, the resulting group of cars in each section of said second track thus having the same destination along the route to be traveled by said train, and coupling the groups of cars in said second track into a complete train blocked for successive delivery by a single movement of said cars along said second track.

4. The method of classifying a plurality of cars for departure from a railroad yard in a train blocked for successive local delivery at several stations, comprising, moving said cars from a receiving area along a single running track; diverting each car from said running track to a second track over a selected one of a plurality of crossovers between said running and said second tracks, the crossover being selected in accordance with the established destination of the corresponding car; holding a diverted car in the section of said second track formed between the selected crossover and the next crossover in the direction of car movement along said running track, and joining all cars occupying said second track after classifying into a complete train ready for departure by a single coupling movement of said cars along said second track.

5. The method of assembling a plurality of cars in a railroad yard into a train blocked for delivery of groups of cars without further shifting to successive locations along the route of travel, comprising, forwarding the cars for said train from a receiving storage area along a single running track, accelerating and decelerating said cars as they move along said running track to effect the proper speed to halt each car at its selected classification storage point, diverting each car from said running track over a crossover track into a storage section of a second track selected in accordance with the established destination of that car, halting each car positively in the section formed in said second track between the crossover over which that car is diverted and the next succeeding crossover, and coupling the classified cars together into train formation by a single reverse movement of said cars along said second track.

6. The method of assembling a plurality of cars in a railroad yard into a train blocked for delivery of groups of cars without further shifting to successive locations along the route of travel, comprising, moving the cars for said train from a receiving storage area along a single running track, controlling the speed of said cars as they move along said running track to obtain the proper speed to halt each car at its selected classificattion storage point, diverting each car from said running track over a crossover track into a storage section of a second track selected in accordance with the established destination of that car, each car stopping in the storage section formed in said second track between the crossover over which that car is diverted and the next succeeding crossover, and coupling the classified cars together into train formation by a single reverse movement of said cars along said second track.

7. In a railroad yard including a single running track and two storage tracks parallel to said running track and on opposite sides thereof, each storage track being connected to said running track by a plurality of crossovers which divide that storage track into a plurality of sections; the method of classifying cars, comprising, propelling cuts of cars to be classified along said running track, preselecting the sections of said storage tracks into which successive cuts of cans are to be diverted over said crossovers, accelerating each cut of cars to assure entry into the corresponding selected section, halting each out within its selected section to hold cars within the assigned sections, and coupling together all cars finally diverted to a storage track by a single reverse movement of the cars along that storage track to form a complete train ready for departure.

8. In a railroad yard including a single running track and two storage tracks parallel to said running track and on opposite sides thereof, each storage track being connected to said running track by a plurality of crossovers which divide that storage track into a plurality of sections; the method of classifying cars, comprising, moving the cuts of cars to be classified along said running track, preselecting the sections of said storage tracks into which successive cuts of cars are to be diverted over said crossovers, controlling .the speed of each cut of cars so that the cut enters the selected section and halts therein, and coupling together all cars finally di verted to a storage track by a single reverse movement of the cars along that storage track to form a complete train ready for departure.

9. The method of classifying a plurality of cars being assembled into a train for departure from a railroad yard, comprising, moving the cars to be classified along a single running track, switching said cars into selected sections of a second track in accordance with the predetermined destination of each car, the resulting group of cars in each section of said second track having the same destination along the route to be traveled by the train, and combining the groups of cars in said second track into a complete train ready for departure by a coupling movement of said cars along said second track.

10. A method of classifying railway cars in a train, by means of a first elongated track having an entrance end and an exit end, and a second elongated track disposed alongside said first track and joined thereto at spaced intervals by cross-over switches connecting said tracks in the direction permitting the car moving on said first track toward the exit end thereof to switch onto said second track without reversing direction, said switches defining on said second track a plurality of sections of sufilcient length to accommodate several cars each, which comprises the steps of propelling the train onto said first track at its entrance end, separating said train into cuts of cars as they move along said first track under rolling momentum, successively switching said cuts onto said second track at selected cross-over switches whereby cars destined for further movement to a common destination are collected together in a selected individual section, retarding said cuts after they roll into said selected sections, and drawing away as a new train cars thus collected in various selected sections, said new train being Withdrawn from said second track by movement in the direction defined by the entrance of said cuts of cars into said sections.

(References on following page) References Cited in the file of this patent UNITED STATES PATENTS Davies June 22, 1909 Dougher Dec. 4, 1923 Richey Dec. 25, 1923 Garlick Nov. 25, 1924 Haines June 1, 1926 Prescott Aug. 14, 1928 Simpson Jan. 7, 1930 Gibbs Aug. 29, 1933 Young Nov. 7, 1939 Lay Oct. 15, 1940 14 Pelican June 3, 1941 Hassler Jan. 26, 1943 Doehler Jan. 15, 1952 Judge Apr. 14, 1953 Hayes Mar. 6, 1956 FOREIGN PATENTS Great Britain Mar. 21, 1956 OTHER REFERENCES Publication: Railroad Gazette for March 8, 1901, vol. 33, page 163, article by Delano and Bromner. 

9. THE METHOD OF CLASSIFYING A PLURALITY OF CARS BEING ASSEMBLED INTO A TRAIN FOR DEPARTURE FROM A RAILROAD YARD, COMPRISING, MOVING THE CARS TO BE CLASSIFIED ALONG A SINGLE RUNNING TRACK, SWITCHING SAID CARS INTO SELECTED SECTIONS OF A SECOND TRACK IN ACCORDANCE WITH THE PREDETERMINED DESTINATION OF EACH CAR, THE RESULTING GROUP OF CARS IN EACH SECTION OF SAID SECOND TRACK HAVING THE SAME DESTINATION ALONG THE ROUTE TO BE TRAVELED BY THE TRAIN, AND COMBINING THE GROUPS OF CARS IN SAID SECOND TRACK INTO A COMPLETE TRAIN READY FOR DEPARTURE BY A COUPLING MOVEMENT OF SAID CARS ALONG SAID SECOND TRACK. 